Thread bobbin and method of producing the same



Oct. 26, 1937; R, BWSON' 2,097,305

THREAD BOBBIN AND METHOD OF PRODUCING THE SAME Filed Nov. 13, 1936 2 Sheets-Sheet 1 I71 06 :1 ti)? Rom/4M) IV AoB/Nso/v Oct. 26, 1937. R ROBlNQN 2,097,305

THREAD BOBBIN AND METHOD OF PRODUCING THE SAME Filed Nov. 13, 1936 2 Sheets-Sheet 2 I11 106 77 {for ROMA/v0 A4 PoB/A/so/v 3 by dmeg Patented Oct. 26, 1937 UNITED STATES THREAD BOBBIN AND METHOD OF PRO- DUCING THE SAME Rowland N. Robinson, Dedham, Mass. Application November 13, 1936. Serial No. 110,687

6 Claims.

This invention relates to thread bobbins and to a method of producing the same.

An object of this invention is to devise a thread bobbinin which the head is securely and non-rotatably fixed to the core in a simple manner.

Another object is to devise a means and method whereby the heads may be automatically and accurately centered around the core ends during the pressing operation.

A further object is to produce such a means and method which will secure the'head to the core non-rotatably as specified above.

A still further object is to secure the heads to the core so that the heads will not collapse in operation even when all of the thread mass has been unwound.

The foregoing and other objects of my invention will be best understood from the following description of exemplifications thereof, reference being had to the accompanying drawings,-

wherein:

Fig. 1 is a cross-sectional view of a bobbin with the heads in position to be forced over the core ends;

Fig. 2 is a cross-sectional view showing the heads forced over the core ends but not secured in place; I

Fig. 3 is a cross-sectional view of the compieted bobbin after it has been pressed to shape and the heads fastened in position;

Fig. 4 is a diagrammatic showing of a mechanism for producing the steps shown in Figs. 1, 2, and 3;

, Figs. 5 and 6" are views showing the mechanism of Fig. 4 in difl'erent stages of producing a bobbin; and

Figs. '7, 8, 9 and 10 show different types of head blanks which may be used. In order to produce my novel bobbin, a mass of thread is cross-wound upon a tubular core 2 of paper or similar compressible material usually used in bobbins. The core 2 is made longer than the depth of the thread mess I so that the ends of the core extend a substantial distance beyond the thread mass as shown. Heads 3 of some suitable material, such as paper, cellulose prodnets, and thelike, are placed opposite the ends of the core 2, as shown in Fig. 1. The heads 3 are each provided with a central opening 4. This opening is preferably made with a diameter of the same size as the inner diameter of the core 2 for areason to be discussed below. mThe heads 3 are then forced down over the .ends of the core 2 to the position shown in Fig. 2.

Since the outer diameter of the core 2 is greater than the diameter of the openings 4, the inner edges of these openings will be turned outward as shown at 5 in Fig. 2. The heads at this time will have a firm grip on the core 2. However, in 5 order to secure these heads in place to the degree which I desire, the outer ends of the core 2 are turned down over the edges 5 to produce the interlocking connection 6 between the edges of the core 2 and the edges of the opening 4, as shown 10 in Fig. 3. During this last step the bobbin may be pressed to shape and size. In pressing the ends of the core 2 to form the interlocking connection 6, the central parts of the bobbin are indented to form the depressions I so that in the 15 completed bobbin the outer ends of the core 2 lie in the same plane as the flat portions of the heads 3.

The bobbin construction described above lends itself admirably to construction by automatic 20 machinery of a very simple type, particularly since the mounting of the heads and the pressing operation may be accomplished at the same time in a single machine. The mechanism diagrammatically shown in Fig. 4 may readily be 25 incorporated in such automatic machinery. This mechanism consists of an elongated punch 8 having a tapered nose 8. The punch 8 moves inside of a press punch l0 arranged concentrically with said punch 8. A space is left between 30 the punch 8 and the press punch ill in which space is placed a crimping tool ll. Thus the crimping tool l is also concentric with the punch 8 and the punch press ill. Facing the punch 8, punch press I 0 and crimping tool II is a similar 35 press assembly consisting of a press punch l2 and a crimping tool l3 substantially identical with the press punch l0 and crimping tool respectively. The crimping tool I3 is provided with a bore l4 into which the punch 8 projects 40 during a portion of the operation. Of course it is to be understood that'each of the members 8, l0, ll,.l2, and I3 are each actuated by suitable operating mechanism to produce the motions to be described below. 45

A core 2 and thread mass I are fed into-position between the two press assemblies. A head 3 is fed into position'adjacent the face of the press punch l0, and another head 3 is fed into position adjacent the face of the press punch l2. The punch 50 8 is then moved to the left in the direction of the arrow in Fig. 4, and by the action of the tapered nose 9 threads itself through the opening in the center of the right-hand head 3. The punch 8 is made substantially of the same diameter as the in- 5D ner diameter of the core 2. Since the opening 4 in the head 3 is also of this diameter, as indicated above, the head 3 automatically centers itself on the punch 8. As the punch 8 moves further to the left, it enters the core 2 and likewise centers said core on said punch. As the motion of the punch continues, it likewise threads itself through the opening in the left-hand head 3, and likewise centers said head upon said punch. This centering of the heads 3 and core 2 is important, since if such centering did not occur, a defective bobbin would be produced.

After the heads 3 and core 2 have been threaded upon the punch 8, the punch continues its travel until it has entered the bore i4 of the crimping tool l3, as shown in dotted lines in Fig. 4. Thereupon the punch 8 serves as a guiding member for the members III, II, i2, and I3 so as to insure an accurate impingement of these members on the bobbin. The bobbin at this time is substantiallyin the condition as'shown in Fig. 1.

The press punches l and I2 are then actuated to approach the bobbin. .This motion pushes the heads 3 along the punch 8, and forces said heads over the ends of the core 2 until said heads reach the thread mass, at which time the press punches Ill and I2 firmly engage the sides of the. thread mass. At this time the bobbin is substantially in the condition as shown in Fig. 2, and the mechanism is substantially in the position as shown in Fig. 5.

During the above travel of the press punches l0 and i2, the crimping tools II and I3 travel with said press punches lagging behind them to the degree substantially as shown in Figs. 4 and 5. The punch presses are then further actuated to compress the thread mass to its final shape.

During the pressing operation the crimping tools I I and I3 are brought forward so that at the end of the pressing operation they are substantially flush with the outer end of the press punches i0 and 12, respectively, as shown in Fig. 6. The crimping tools, therefore, turn over the ends of the core 2 to produce the interlocking connections 6 and also the depressions 1. At the end of this pressing step, the bobbin is completed substantially in the form as shown in Fig. 3. The punch 8 is withdrawn first and then the members I0, I I, I2, and 13 are withdrawn, whereupon the completed bobbin drops out of the mechanism. The operation may then be carried out again upon the next bobbin.

The heads 3, which may be used, are usually circular in shape but the opening 4 may assume anyconvenient form as long as the principles described above are satisfied. For example, the opening 4 may be circular as shown in Fig. '7. The opening may be provided with a number of slits [5, as shown in Fig. 8, to facilitate the turning back of the edges to the position shown in Fig. 2. This enables stiffer materialto be used in some cases. A still further form is shown in Fig. 9 where the opening 4 is provided with a series of projections I6. The diameter formed by the inner ends I! of the projections I6 is preferably the same as the inner diameter of the core 2. The projections need not be pointed as shown, but may be of any other shape, such as, for example, are shown in Fig. 10 where projections 18 of oblong shape are provided. If it is desiredto supply a greater amount of material from the head 3 to form the interlocking connection 6, the diameter of the hole 4 may be made somewhat smaller than the inner diameter of the core 2. In each case where the diameter of the hole 4 is specified,

tendency to move inwardly and collapse when the last few turns remain upon the core. The novel bobbins described herein retain the heads so firmly in place that all of the thread may be unwound without the heads 3 collapsing.

This invention is not limited .to the particular details of construction, materials, or processes as described above, as many equivalents will suggest themselves to those skilled in the art. It is accordingly desired that the appended claims be given a broad interpretation commensurate with the scope of the invention within the art.

What is claimed is:

1. A thread bobbin comprising a tubular core, a thread mass wound on said core, and a head mounted on each end of said core overlying the ends of said thread mass, each head having a central opening surrounding an end oi'said core, the edge of said opening and the wall of said core at said end being .bent into transversely arcuate interlocking relation.

2. A thread bobbin comprising a tubular core, a thread mass wound on said core, and a head mounted on each end of said core overlying the ends of said thread mass, each head having a central opening surroundingv an end of said core,

the diameter of said opening being equal to or less than the inner diameter of said core, each head being located over an end of said core, the edge of said opening and the wall of said core at said end being bent into transversely arcuate of said coreover each end of said core, turning the edges of said opening outwardly to lie closely along the outer walls of said core, pressing" said thread mass to shape and pressing upon the outer ends of said core to turn back said outer core ends and said outwardly-turned head edges to iorm 'an interlocking connection with each other.

4. The method of making a thread bobbin comprising the steps of winding a thread mass upon a tubular core so as to leave the ends of said core projecting beyond said thread mass, thread- I ing a head having a central opening with a diameter equal to or less than the inner diameter of said core upon an elongated'punch having a diameter substantially equal to the inner diameter of said core, threading said core upon said punch, threading another head similar to said first head upon said punch, forcing said heads along said punch over the core ends into intimate contact with the ends of said thread mass, turning the edges oi said opening outwardly to lie closely along the outer walls of said core, pressing said thread mass to shape and pressing upon the outer ends of said core to turn back said outer core ends and said outwardly-turned head edges into interlocking connection with each other.

5. A'thread bobbin comprising a tubular core. a thread mass wound on said core, and a head mounted on each end of said core overlying the ends of said thread mass, each head having a round central opening surrounding an end of said core, the diameter of said opening being smaller than the outside diameter of said core, each head being located over an end of said core, the edges of said opening and the walls of said core at said end being bent into transversely arcuate inter-' locking relation.

6. A thread bobbin comprising a tubular core,

0 a thread mass wound on said core, and a head walls of said core at said end being bent into transversely arcuate interlocking relation.

ROWLAND N. ROBINSON. 1o 

